Field of the Invention
The invention relates to a press for the expressing of liquid-containing substances, in particular, of agricultural and chemical products. The press has a closed container, at least one press diaphragm subdividing an interior of the container into a pressure medium space and a press medium space. The container casing has disposed in it a filling and emptying orifice that is capable of being closed by a cover and that is associated with a juice discharge located in the press medium space. Liquid-permeable flexible or elastic drainage elements are disposed in the container interior for large-volume juice extraction that include at least one supporting element and a hose disposed around the latter and being of juice-permeable material.
Such presses are known, for example, from European Patent 0 145 948 B1 and are used for expressing the grape juice used as the initial substance for wine production out of grapes introduced into the press. The press described in EP 0 145 948 B1 has a closed container that can be set in rotation about its horizontal longitudinal axis. Located in the casing of the container is a filling and emptying orifice that is disposed opposite a juice discharge provided on the opposite side of the container and that can be closed by a cover. Along the diametral region of the container, drainage elements in the form of liquid-permeable tubes are provided, which are located in a press space defined by a press diaphragm that is tight to pressure medium and is fastened inside the container and that subdivides the container interior into a pressure medium space and the press space.
Commonly assigned international application PCT/EP01/03962, published WO01/76857, describes a press that includes a closed container capable of being set in rotation about its horizontal longitudinal axis. The container interior is subdivided into a pressure medium space and a press medium space by at least one press diaphragm, and a filling and emptying orifice capable of being closed by disposing a cover in the container casing. The filling and emptying orifice has located opposite it a juice discharge located in the press space. Furthermore, the press space has disposed in it liquid-permeable drainage elements that are disposed over the diameter and substantially perpendicularly to the container axis and that extend from one end of the container to the other end of the container. The drainage elements are formed by an elastic or flexible supporting element, around which a juice-permeable fabric hose is disposed. In the juice extraction position, the drainage elements extend in a substantially vertical direction to feed the juice into a juice-collecting nipple that is located underneath and from which the juice is delivered to a collecting container through a collecting line.
In the presses described above, what is critically important is that the parts, in particular, the drainage elements, coming into contact with the batch during pressing can be demounted in a simple way for cleaning purposes and can be mounted within the container again after the cleaning operation. In such a case, it is particularly important that the demounting and, also, the cleaning of the drainage elements and of the container interior can take place from outside because the climbing of persons into the container entails an appreciable risk or is even forbidden by safety regulations.
In the presses described above, there is, in such a case, the problem that the drainage elements must withstand the pressures acting on them from outside so that a sufficient juice discharge is always ensured. Particularly where large presses are concerned, the problem in this case arises that the drainage elements, provided with metal reinforcing elements to increase strength, have a very high weight so that they can no longer be inserted in the interior of the container by only one operator.